Leaking Carb, petcock to blame?

[fiveohindc]

My right side carb started leaking near the drain screw not so long ago. Enough to leave a stain on the ground after it sat overnight. I'm leaving for Europe and didn't want gas all over the yard when I return so I drained the right carb and left it there yesterday AM. Now there's even more gas spilling out!

So naturally I thought, the petcock must be leaking and overfilling the carb. Well, best I can determine neither of the petcocks are leaking. Maybe sweating out a drop here and there, but not enough to fill that bowl overnight (plus the lines look dry). I believe I have the non-vacuum petcocks if that matters.

I've drained BOTH bowls now, but I'm not sure how to attack this problem when I get back from vacation. I very much want to learn about rebuilding the carbs and cleaning them, and have found many write-ups. However, I"m a visual learner-- does anyone have a step by step with photos? I saw a petcock rebuild on here with photos-- would be so helpful if anyone could link me to one for carbs!

 

[littlebill31]

I'm going to say float assembly. The float stops the fuel flow. If it is off, then it can allow fuel to fill the bowl. However, it could possibly be the float valve needle or O-ring not sealing either.
I would pull the fuel line from the carbs and plug it. This will stop the flow until you get home. Then attack the carbs.
Technically, if the floats are working, and the petcock is on, the float should still stop the flow from filling the bowls. Know what I mean?
But a leaking petcock can still cause problems like this.

One test to try: If you remove the fuel line and let it "dangle", petcocks closed, does it leak?

 

[Downer]

I had the same issue adjusted floats many times got new float needle and seats still dripping going crazy trying to figure it out it was my petcock leaking very very slowly put an in line pet cock in cause it was cheaper to do so no more leaking

 

[weekendrider]

Search for BS CV carb tutorial, it is on the site.....somewhere.

 

[fiveohindc]

Thanks guys. About to leave town today, and of course I came out and MORE gas leaking from the carbs. So I drained it all from the tank and the carbs, and I'll have to worry about it when I get home.

Here's the thing-- It has to be a slow leaking petcock, right? If I drained both bowls and turned off the fuel supply, only to find more fuel leaking two days later, it had to come from the petcocks. But is the problem two-fold because the carbs flood out? Or is that just a normal response (as though I left the petcocks open).

I also find it funny that the one leaking is the right side carb, where gravity would tell me that more gas would be in the LEFT carb causing it to run out there (it's on the side stand).

Could the culprit be the cold (first time since I bought this bike that it's gotten near freezing at night) shrinking every damn rubber? I'm so obsessive I'm practically dreading leaving town-- because I want to solve this thing so bad. At least know what I need to buy, tear into, etc.

 

[XSLeo]

The floats and float valves are not a shut off device. If they were then why use petcocks?
The floats and float valves are metering devices. The cintrol the amount of fuel in the bowl. Even if they work perfectly fuel can still over flow the float bowls because of leaky pet cocks. One easy way to check petcocks is to unhook the fuel line from the pet cock, run a new line from the petcock to a can or jar. Leave it set over night. Is fuel in the can or jar? If so your petcock leaks. If your bike has two petcocks check both.
Even if just one leaks it can overflow both carbs because there ie a fuel crossover between the carbs.
fiveohindc, you don't say what year your bike is. The standard petcocks were used as a set of two up to 78 I think it was, then they ent to two vacumm petcocks, then in 80 they started using just one vacumm petcock.
Easy to tell the difference. The standard is marked off/on/res, the vacumm are pri/on/res.
Leo